Endoscopic surgical techniques allow a surgical procedure to be performed on a patient's body through a relatively small incision in the body and with a limited amount of body tissue disruption. Endoscopic surgery typically utilizes a tubular structure known as a cannula which is inserted into a small incision in the body. The cannula holds the incision open and serves as a conduit extending between the exterior of the body and the local area inside the body where the surgery is to be performed.
Due to the relatively small size of the passage into the body which is defined by the cannula, certain surgical procedures, such as posterior discectomies and procedures using steerable surgical instruments, have been difficult to perform using endoscopic techniques.